DropDownListFor報告類型不匹配

Question

模型：

    [Required(ErrorMessage = "You must assign this user a role")]
    [Display(Name = "Role")]
    public string UserRole { get; set; }

    public IEnumerable<System.Web.Mvc.SelectListItem> UserRoles { get; set; }

控制器：

    public ActionResult CreateNewUser()
    {
        CreateNewUserModel model = new CreateNewUserModel();
        model.UserRoles = new []
        {
            new SelectListItem{Value="Administrator", Text="Administrator"},
            new SelectListItem{Value="User", Text="User"}
        };
        //model.UserRole = "Administrator";
        return View(model);
    }

視圖：

    @Html.DropDownListFor(x => x.UserRole, Model.UserRoles,"Select a role")
    @Html.ValidationMessageFor(x=>x.UserRole)

加載用於創建新用戶的頁面時，出現異常，指出UserRole must be of type IEnumerable<SelectList>

Answer 1

嘗試更改：

model.UserRoles = new []
    {
        new SelectListItem{Value="Administrator", Text="Administrator"},
        new SelectListItem{Value="User", Text="User"}
    };

至：

model.UserRoles = List<SelectListItem>
    {
        new SelectListItem{Value="Administrator", Text="Administrator"},
        new SelectListItem{Value="User", Text="User"}
    };